Paper web unwinder shoe brake



July 15, 1969 MOORE ET AL 3,455,192

PAPER WEB UNWINDER SHOE BRAKE Filed Feb. 21, 1966 f 5 z Z5 WNW/N057? "FORE lawezzae/i 17 002 6 United States Patent 3,455,192 PAPER WEB UNWINDER SHOE BRAKE Lawrence A. Moore, King of Prussia, Pa., and Edward J.

Klaczkiewicz, Wilmington, Del., assignors to Beloit Eastern Corporation, Downingtown, Pa., a corporation of Delaware Filed Feb. 21, 1966, Ser. No. 529,076 Int. Cl. B26d 7/14, 5/14, 7/06 US Cl. 83-175 5 Claims ABSTRACT OF THE DISCLOSURE The invention is directed to a web tension control system which incorporates a pair of pivotable arms secured at opposite sides of a rotatable drum. The arms include brake shoes secured to the ends thereof and engageable with the drum while the opposite end of the arms engage expansible chambers to cause rotation of the arms about their pivot points. The arms are pivoted in such a manner as to utilize the full efl 'ects of gravity to disengage the brake shoes from the drum.

During this portion of the paper web converting process, the tension of the web passing from the unwinder roll to the take-up or winder roll must be controlled to a substantially constant predetermined tension. Therefore, a brake system is required to control the speed of rotation of the unwinder roll from which the paper web is drawn.

Heretofore, brake systems used to control the operation of unwinder rolls have been relatively complex requiring intricate and continual adjustment for proper operational performance. Furthermore, the construction of prior brake systems is such that maintenance accessibility is inconvenient. Also, prior brake systems require an excessive number of intricately machined parts. In addition, brake systems of prior art have been large and awkward, and the arms used to apply brake pressure to control an unwinder roll extend upwardly from their associated brake drum retracting from the overall convenience and operation of the brake system.

Therefore, one of the primary objects of the present invention is to provide a brake system for unwinder rolls which is relatively simple and which has a minimum number of component parts.

Another object of the present invention is to provide a brake system for unwinder rolls which requires little or no periodic adjustment.

Another object of the present invention is to provide a brake system for unwinder rolls which is constructed such that maintenance accessibility is convenient.

Yet another object of the present invention is to pro vide a brake system for unwinder rolls wherein the load arms, which are used to apply brake pressure to an associated brake drum, require no biasing means to disengage the brake shoes from the brake drum.

Still another object of the present invention is to provide a brake system which is operable from an air supply and which brake system is controlled by a tension-sensing device associated with the web moving between the rolls.

A feature of the present invention is a pneumatic cham- 3,455,192 Patented July 15, 1969 ber which is inflated from an air supply via a control valve, thereby controlling the brake pressure applied to a brake drum.

Briefly, the brake system of the present invention has a support means which carries the brake drum. The brake drum is connected to an unwinder roll to rotate with it. A pair of arms are pivotally mounted on support means so that a portion of the arms extends adjacent the brake drum and the other portion of the arms extends adjacent the support means. A pneumatic chamber is positioned between the support means and each of the pivotal arms for urging the opposite end of the arms against the brake drum when the chamber is inflated.

By using a pair of pivotal arms and a pair of inflatable chambers to move the arms, brake adjustment of the arms to obtain uniform brake pressure is obviated. Therefore, when a paper web is transported from an unwind roll to a slitter, or the like, and then to a wind-up roll, the present invention provides simple and inexpensive means for controlling the tension of the web moving between the rolls.

These and other objects and features of the invention will be more fully realized and understood from the following detailed description when taken in conjunction with the accompanying drawings in which:

FIGURE 1 is a schematic representation of the brake system of the present invention used in conjunction with a pair of wound rolls; and

FIGURE 2 shows the detailed construction of a pneumatically controlled brake which is constructed in accordance with the principles of this invention.

As seen in FIGURE 1, a web 10 is transported from an unwind roll 11 to a wind-up roll 12. The web moving between the rolls 11 and 12 is in contact with a slitter 13 for trimming or cutting the web into narrow continuous sheets.

A tension-sensing device 14 is positioned adjacent the web 10 between the roll 11 and the slitter 13. The tensionsensing device 14 may be a mechanical, fluid or electrical or pneumatic device, as desired, to develop control signals indicative of web tension. A brake system 16 is mechanically coupled to the roll 11 to control the retardation of rotation of the roll 11. A control valve 17 is connected between the tension-sensing device 14 and the brake system 16. Control signals from the device 14 operate the valve 17 in such a manner as to control the operation of the brake system 16.

An air supply 18 is connected to the control valve 17 for applying air pressure to the brake system 16. The amount of air pressure varies in accordance with the signals received from the tension-sensing device 14.

For a better understanding of the construction of the brake used in the brake system 16, reference is now made to FIGURE 2. A support 20 is provided with a pair of bosses 21 and 22 which are secured to the upper end of the support. A brake drum 23 is positioned adjacent the support 20 and between the bosses 21 and 22. The drum 23 is connectible to the unwinder roll 11 of FIGURE 1, for rotation therewith. An unwinder drive 24 is connected to the drum 23 to drive the drum 23 and the unwinder roll 11.

An arm 26 is pivotally connected to the boss 21 by a pin 27. Similarly, an arm 28 is pivotally connected to the boss 22 by a pin 29. A pair of brake shoes 30 and 31 are secured to the arms 26 and 28, respectively, for applying frictional force to the brake drums 23, thereby controlling the retardation of rotation of the drum 23 and the unwinder roll 11. A pair of resilient pneumatic chambers 32 and 33 are positioned between the support 20 and the lower portion of the arms 26 and 28, respectively, as seen in FIGURE 2. A pair of pressure pads 34 and 35 are positioned on opposite sides of the resilient pneumatic chamber 32 to provide a substantially uniform surface for engagement with the pneumatic cylinder 33. Similarly, a pair of pressure pads 36 and 37 are positioned on opposite sides of the resilient pneumatic chamber 33.

The upper end 26' of the arm 26 is positioned outwardly from the pin 27 to cause the arm 26 to tend to rotate about the pin 27 in the direction indicated by the arrow A. This feature eliminates the need of biasing means to disengage the brake shoe 30 from the surface of the brake drum 23. Similarly, the upper end 28' of the arm 23 extends outwardly from the pin 29 to tend to rotate the arm 28 about the pin 29 in the direction indicated by the arrow B.

The control valve 17 is in fluid communication with the pneumatic chambers 32 and 33 via an air line 38. There fore, when the tension-sensing device 14 senses variations in the web tension, the control valve 17 will vary the amount of air delivered to the pneumatic chambers 32 and 33 which, in turn, control the brake pressure applied to the drum 23 by the brake shoes 30 and 31. By utilizing two pneumatic chambers to control movement of the arms 26 and 28, which are positioned on opposite sides of the brake drum 23, the brake system of the present invention requires no adjusting means to adjust the position of one arm relative to the other.

In summary, the present invention has provided a simple and etficient means for controlling the brake pressure applied to a brake drum which, in turn, controls the retardation of rotation of the unwinder roll 11. Furthermore, the present invention has provided a brake system which obviates the need of biasing means to urge the brake shoes 30 and 31 away from the surface of the drum 23. Furthermore, the present invention has provided a pneumatically controlled brake system which is conveniently accessible for maintenance and which obviates the need of continual brake adjustment for proper operational performance.

It will be understood that variations and modifications may be effected without departing from the spirit and scope of the novel concepts of the invention.

What is claimed is:

1. A brake system for controlling the retardation of rotation of a roll on a web unwinder, including:

a brake drum;

an unwinder roll support;

means for connecting said brake drum to said unwinder roll support;

shoe means engageable with said drum for applying frictional force to said drum, said shoe means including a pair of opposed shoes carried on upper ends of pivotable arms and further including fluid control means acting on the lower ends of said arms to cause said opposed shoes to engage said brake drum, said arms having a pivot point located between the center of gravity of the arms and the axis of the drum so that brake means connected to said first roll, said brake means comprising a support, first and second bosses on said support, a brake drum positioned adjacent said support between said first and second bosses and rotatably connected to said first roll, first and second arms each having two ends, said arms pivotably connected to said bosses at a point on said arms intermediate their ends, one end of said arms terminating adjacent said drum and the other end of said arms terminating adjacent said support, the ends of said arms being movable in a plane perpendicular to the axis of rotation of said drum, and first and second pneumatic chambers positioned between said support and the portion of said first and second arms adjacent said support for urging the portion of said arms adjacent said drum against said drum to control the speed of rotation of said first roll in response to said sensing means.

3. The brake system of claim 2 further including brake shoes secured to the portions of said first and second arms adjacent said drum for making frictional contact with said drum.

4. The brake system of claim 2 further including a slitter positioned between said first and second rolls and in engagement with the web moving therebetween for slitting the web.

5. The brake system of claim 2 wherein said first and second arms are pivotably connected to said bosses in such a manner as to cause said arms to become disengageable from said drum by gravitational force.

References Cited UNITED STATES PATENTS 731,530 6/1903 Wood. 1,645,939 10/1927 Smith 242-75.43 1,888,549 11/1932 Crafts 24275.43 2,675,191 4/ 1954 McGraW 242-75.43 2,964,440 12/ 1960 Stevens 242-75.43 X 2,983,463 5/1961 Aaron et a1 24275.43

JAMES M. MEISTER, Primary Examiner US. Cl. X.R. 

